html { overflow-x: hidden; overflow-y: auto; }
.login_title {	
	padding-top: 40px;
	font-size: 60px;
	text-align: center;
	font-weight: 900;
}
.login_title_30 {	
	padding-top: 40px;
	font-size: 30px;
	text-align: center;
	font-weight: 900;
}

.login_name {
	padding-top: 0;
	padding-bottom: 0;
	-moz-box-sizing: border-box;
	-webkit-box-sizing: border-box;
	box-sizing: border-box;
	height: 140px;
	*height: 136px;
	-moz-box-sizing: border-box;
	-webkit-box-sizing: border-box;
	box-sizing: border-box;
	font-size: 100px;
	text-align: center;
	font-weight: 700;
}

.video_btn{
    position: relative; /** 相对布局 **/
}
.video_btn:hover{
    top: 2px; /**向下偏移2px **/
    cursor: pointer
}

.div_left {
  overflow: auto;
  height: calc(90vh)
}
.div_left::-webkit-scrollbar {
	border-width:1px;
}